1. Field of the Invention
The invention pertains to a system which greatly reduces or prevents altogether the injuries and property damage and consequent suffering, deaths and expense incident to motor vehicle collisions. The invention accomplishes this result by providing the motor vehicle with novel means which cooperate to absorb the energy of impacts in such a way as to minimize the harmful effects of collisions on the vehicle and its occupants and to minimize damage or injury to other vehicles, property, pedestrians, cyclists, animals, etc. struck by or in collisions with the vehicle constructed and equipped according to the invention. These results are achieved with minimum permanent distortion or other damage to the vehicle. Thus medical and repair bills and insurance costs are greatly reduced.
2. Background of the Invention
Conventional metal automobile bumpers and bodies are totally inadequate from the standpoints of damage and safety because, with them, even at such low parking lot speeds as five to ten miles an hour the repair bills normally run to hundreds of dollars per collision while many deaths and injuries and more than 75% of property damage arise in accidents occurring at speeds not over thirty miles per hour. The severity of injuries and damage tends to increase geometrically with, i.e. with the square of, the speed of collision. The result is an astronomical burden of death, injury, suffering and property damage.
Prior art workers have endeavored in many ways to reduce the severity of the consequences of automobile accidents, but no truly effective solution deemed worthy of wide adoption, at reasonable costs, and not entailing serious disadvantages has heretofore been proposed.
During 1958, Cornell Aeronautical Laboratory, Inc. conducted tests (described in its unpublished Report No. YB-1004-D-5) for United States Rubber Company which indicated that for crash impacts up to approximately only 8 miles per hour the effectiveness of conventional metal automobile bumpers mounted on brackets extending away from the chassis could be enhanced by providing a metal back-up plate about six inches behind the bumper and filling the space between the bumper and the back-up plate with a lightweight energy-absorbing material known as No. 22266 "Ensolite" (trademark) manufactured by United States Rubber Company, together with supporting leaf springs. In the tests the car equipped with this narrow horizontal bumper was caused to collide with a vertical telephone pole. In this relatively infrequent type of accident, the shock-absorbing frontal area of the "Ensolite" was only about 360 square inches and in the collision only a fraction of this small area was brought vigorously into play. Consequently the Cornell tests had no impact whatever on the art and amounted to merely abandoned experiments.
Recently water bumpers have been used to a limited extent, particulary by taxi fleets. Such bumpers are described in Consumer Reports for September 1969, pages 514-515. While they can reduce vehicle damage at speeds up to 10 miles per hour, at higher speeds the bumper itself is usually damaged and at speeds of the order of 20-30 miles per hour extensive damage to the vehicle itself and passenger injury occur. Moreover, unless the heights of the narrow bumpers involved match one another, the water bumpers have little or no effect even at low speeds such as are encountered in parking collisions. Also they increase the vehicle length by about 12 inches, increase the vehicle weight by about 100 pounds and have to be filled with water and antifreeze, which are sprayed into the air during collisions. Water bumpers do not begin to approach in effectiveness the safety system of the present invention which is highly effective in reducing injuries and damgage at much higher speeds than those for which the water bumper is useful. The relative ineffectiveness of water bumpers is partly due to the fact that they are narrow and transmit the force of the collision to the chassis only, in line with conventional automobile bumper design. This is in contrast to the present invention in which the force of collisions is transmitted to the entire frontal or rear end area of the vehicle. For a water bumper to protect the entire front end of an automobile and provide sufficient stroke length for collisions at moderate driving speeds, it would have to weigh more than 500 pounds. Corresponding rear end protection would add at least 250 pounds to the weight of the vehicle.
Another recent development which has resulted in reports of rather good crash test results at speeds up to 25-30 miles per hour has involved the use of metal bumpers backed by metal shock absorbers filled with compressible silicone rubber, mounted on conventional metal automobiles. However this proposal undoubtedly requires extra weight, extra overall vehicle length, and high costs, fails to protect pedestrians, the fenders and bodies of other vehicles, or stationary objects hit by vehicles, fails to reduce the damage vulnerability of present metal bodies, fails to give adequately increased protection to vehicles or passengers in lateral collisions or roll-over, and fails to distribute part of the collision forces directly to vehicle bodies and engines as well as to chassis, in contradistinction to the present invention.
A major automobile producer has recently indicated (Chemical Week for Nov. 5, 1969, page 21) that promising results are now being obtained with a rubberized bumper consisting of a porous rubber compound, evidently employing a tripolymer based on neoprene having high restorability characteristics, wrapped around a heavy gauge metal frame. However, this falls far short of the present invention and would not be nearly as effective.
Another type of narrow bumper of conventional dimensions which has been recently developed is one based on a core or body of cellular polyurethane coated with a protective non-cellular skin of polymeric material. However, because of the inherent limitations of the design of this type of bumper, it gives only very limited protection to the vehicle and almost no protection to its occupants.
Inflatable air bags which are located in the passenger compartment and inflated instantaneously upon collision are now the subject of much experimentation. However, these do not protect the vehicle from damage and moreover are themselves subject to certain serious disadvantages such as limited reliability and the possibility of injury to individuals of weights and sizes or sitting positions different from those for which speicific air bags were designed. Nevertheless, if and when inflatable air bags are perfected, they could be used in conjunction with major features of the present invention as alternate or complementary interior protection for occupants.
Interior seat belts have long been used in vehicles to reduce injuries to occupants. They have the advantage of decelerating the occupant simultaneously with the deceleration of the crashing vehicle. However, conventional vehicle decelerations during collisions are often erratic, exerting severe shocks, and the narrow belts can exert injuriously severe restraints on parts of occupants' bodies during severse shocks. Moreover, occupants often fail to fasten their seat belts, rendering them useless.
Present interior crash pads of vehicles are generally made of relatively stiff material which can injure occupants. They are located too low relative to occupants' bodies to prevent them from hurtling against or through windshields. They are also too narrow to decelerate occupants without injury even in moderately severe collisions. Finally, they are located too far away from vehicle occupants, so that occupants may strike these pads at nearly full collision speeds after the vehicles have already been brought to complete stops.